from collections import deque

X,Y=map(int,input().split())

DP=[[10**6]*600 for i in range(600)]

# DP[0][0] は(-300,-300)

Q=deque()

for i in range(600):
    DP[i][i]=0
    Q.append((i,i))

while Q:
    x,y=Q.popleft()

    x1=x-300
    y1=y-300

    if DP[y][x]>DP[x][y]+1:
        DP[y][x]=DP[x][y]+1
        Q.append((y,x))

    if (x1+y1)%2==0:
        x2=(x1+y1)//2
        y2=(x1-y1)//2
        #print(x1,y1,x2,y2)

        if 0<=x2+300<600 and 0<=y2+300<600 and DP[x2+300][y2+300]>DP[x][y]+1:
            DP[x2+300][y2+300]=DP[x][y]+1
            Q.append((x2+300,y2+300))

if DP[X-300][Y-300]>=10**5:
    print(-1)
else:
    print(DP[X-300][Y-300])